#pragma once
// MySQL 版本
#include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
#include <fstream>
#include <cassert>
#include <cstdlib>

#include "../comm/log.hpp"
#include "../comm/util.hpp"
#include "include/mysql.h"

// 根据题目list文件，加载所有的题目信息到内存中
// model : 主要用来和数据进行交互，对外提供访问数据的接口


namespace ns_model
{
    using namespace ns_log;
    using namespace ns_util;

    struct Question{
        std::string number;   // 题目编号， 唯一
        std::string title;    // 题目的标题
        std::string star;     // 难度：简单 中等 困难
        std::string desc;     // 题目的描述
        std::string header;   // 题目预设给用户在线编辑器的代码
        std::string tail;     // 题目的测试用例，需要和header拼接，形成完整代码
        int cpu_limit;        // 题目的时间要求(S)
        int mem_limit;        // 题目的空间要求(KB)
    };
    const std::string oj_questions = "oj_questions";
    const std::string host = "127.0.0.1";
    const std::string user = "oj_client";
    const std::string passwd  = "123456";
    const std::string db = "oj";
    const int port = 3306;

    class Model
    {
    
    public:
        Model()
        {
        }
        bool QueryMySQL(const std::string &sql, std::vector<Question> *out)
        {
            // 创建数据库句柄
            MYSQL *my = mysql_init(nullptr);

            // 连接数据库
            if(nullptr == mysql_real_connect(my,host.c_str(), user.c_str(), passwd.c_str(), db.c_str(), port, nullptr, 0))
            {
                LOG(FATAL) << "连接数据库失败！" << "\n";
                return false;
            }
            // 设置编码格式
            mysql_set_character_set(my, "utf8");

            LOG(INFO) << "连接数据库成功" << "\n";

            // 执行sql语句
            if(0 != mysql_query(my, sql.c_str()))
            {
                LOG(WARNING) << sql << "execute error" << "\n";
                return false;
            } 

            // 提取结果
            MYSQL_RES *res = mysql_store_result(my);

            // 分析结果
            int rows = mysql_num_rows(res);
            int cols = mysql_num_fields(res);

            Question q;

            for(int i = 0; i < rows; i++)
            {
                MYSQL_ROW row = mysql_fetch_row(res);
                q.number = row[0];
                q.title = row[1];
                q.star = row[2];
                q.desc = row[3];
                q.header = row[4];
                q.tail = row[5];
                q.cpu_limit = atoi(row[6]);
                q.mem_limit = atoi(row[7]);

                out->push_back(q);
            }
            // 释放空间
            // free(res);

            // 关闭数据库
            mysql_close(my);
            return true;
        }
        bool GetAllQuestions(std::vector<Question> *out)
        {   
            std::string sql = "select * from ";
            sql+=oj_questions;
            return QueryMySQL(sql, out);
        }
        bool GetOneQuestion(const std::string &number, Question *q)
        {
            std::string sql = "select * from ";
            sql+=oj_questions;
            sql+=" where number=";
            sql+=number;
            std::vector<Question> result;
            if(QueryMySQL(sql, &result))
            {
                if(result.size() == 1)
                {
                    *q = result[0];
                    return true;
                }
            }
            return false;
        }
        ~Model()
        {}
    };
}

